Device for the wet treatment of artificial threads



June 5, 1956 K. J. SCHULZE 2,748,587

DEVICE FOR THE WET TREATMENT OF ARTIFICIAL THREADS Filed April 15, 1951FIG- 1 FIG- 2 FIG- 3 FIG 4 FIG. 5

FIG. 8

KURD J- SCHULZE INVENTOR.

BY Wmcflmw PM ATTORNEYS United States Patent i) DEVICE FOR THE WETTREATMENT OF ARTIFICIAL THREADS Kurd Jiirgen Schulze, Oberbruch,Germany, assignor, by mesne assignments, to American Enka Corporation,Enka, N. C., a corporation of Delaware Application April 13, 1951,Serial No. 220,769

Claims priority, application Germany April 17, 1950 2 Claims. (Cl.68-205) This invention relates to a device for the wet treatment ofartificial threads.

Interinclined pairs of rolls are frequently used in the production ofartificial threads by a continuous process. Since it is essential to usea series of wash liquids in the after-treatment of threads, especiallyin the viscose process, it is difficult to construct pairs of rollswhich ensure that the individual after-treating baths are meticulouslyseparated from one another. The principle of separate indentationenables considerable improvements to be made since in this way it ispossible to prevent the baths from being mixed on the rolls. It is onlypossible to work economically and without interruptions when theindividual bath liquids are prevented from mixing on the after-treatingrolls and when the quantity of washing liquid entrained by the runningthread is kept as small as possible. Previous proposals did not givesatisfactory results in the latter respect. According to the previousproposals too much of the bath liquid was entrained which caused thethread to slide unsteadily over the rolls so that the thread windingsran over one another which led to the threads becoming entangled andsubsequently broken.

Extensive experiments have shown that this disadvantageous effect is dueto the shape of the surface of the lower of the two interinclined rolls.When the surface of the lower roll is smooth or provided with capillaryfiutings it forms too thick a film of liquid from which the ascendingthreads carry away too much liquid with them to the upper roll.

It is an object of this invention to provide apparatus which willovercome the above disadvantages.

Other and further objects of the present invention will become apparentfrom the following description and appended claims taken together withthe accompanying drawings, in which:

Figs. 1 through 5 are end views of rolls having a surface configurationaccording to the present invention;

Fig. 6 is a perspective view of a portion of the surface of a rollaccording to the present invention;

Fig. 7 is an end view of two inclined rolls according to the presentinvention; and

Fig. 8 is a side elevation view of the rolls according to Fig. 7.

It has now been found to be of great advantage for uninterrupted workingif the threads ascending from the lower to the upper roll have as thinas possible a liquid sheath since otherwise the individual turns of thethread spiral readily adhere together on contact which leads to breakageof the thread. It is also important that the thread passing from oneafter-treating station to another should have as thin as possible aliquid sheath in order to keep the circulating wash baths clean. Sincethe fresh supply of after-treating liquid takes place on the upper rollit is naturally also desirable that the threads should carry as small aspossible a part of the bath back to the upper roll again since, if thereis too great a circulation of after-treating liquids, the concentrationand, in the case of hot bath liquids, the temperature also suffer toogreat a variation. If the threads have too thick a liquid sheath thenthe ascending threads become very unsteady due to the formation of aliquid seal between the threads and the upper roll, the surface tensionforces of which tear individual capillary threads and produce a tangle.

The experiments also showed that the above-described disadvantages whichresult from a thick liquid sheath around the ascending turns of threadcan be removed by coarse longitudinal fluting of the lower roll of theinterinclined pairs of rolls. The longitudinal fluting must be of such ashape that it has a profile tapering outwardly at an acute angle. Forexample, all triangular profile shapes having straight, convex orconcave, convergent side faces are suitable for the purpose. Truncatedpyramidal profiles can also be used or profiles which taper to two ormore tooth edges. Preferably the longitudinal profiles are such thatthey give a zigzag separated indentation at the segmental limits of theroll. A surface shaped in this way has a very small capacity forretaining liquid so that the threads can carry only very little bathliquid with them. The surface of contact of the roll with the thread isalso reduced considerably. This causes the liquids to be sprayed oifvigorously. The liquids are not rejected from a single part only of thethread windings in a large quantity but the rejection of liquid isdistributed over the whole sector of the roll. As a result of thisarrangement the ascending thread carries down the whole quantity ofliquid which is supplied afresh to the upper roll but so much of thebath liquid is sprayed off by the lower roll that the ascending threadonly carries with it about a quarter to one-third of the quantity whichit carried with it as it ran on to the lower roll. A particularembodiment of the present invention will now be specifically described.

In Figures 1 to 5 are illustrated terminal views of rollers, which areprovided with grooves running parallel to the axis, or ledges runningbetween these grooves, of approximately triangular cross-section in thesense of the invention. The grooves and ledges are shown on only a partof the cylinder circumference; they extend, however, over the entirecircumference, as is also evident from Figures 7 and 8.

According to Figure l, the projecting parts of the roller surfacedesignated by 1 having a triangular cross-section, which is delineatedby straight lines. In Figure 2, the cross-section of the ledges 2 isdelineated by convex lateral lines. According to Figure 3 thedelineating lines of the ledges are concave. The cross-sections of theledges 4 in Figure 4 exhibit two straight side lines and a blunt tip,and in Figure 5, the cross-sections of the ledges 5 are delineated bydoubly concave lateral lines.

Figure 6 shows a section from the envelope of a lower roller, as it isused according to the invention for the Wet treatment of threads,whereby for example, a hollow cylinder serves, whose surface exhibitsthe longitudinal grooves according to the invention. The cylinderenvelope is interrupted in a zigzag form at 6 and 7. This interruptionextends over the entire circumference of the roller body or of thehollow cylinder, as is clearly shown in Figure 8. The zigzag shaped endsof the two roller parts 8 and 9 according to Figure 6 engage in eachother, but nevertheless leave open a slit 10 through which the liquidflowing in the longitudinal grooves of the roller can flow 0E, withoutbecoming mixed with the liquid of the adjacent roller section. Besidesthe interruption by the slit 10, the roller surface can, of course,exhibit still further similar interruptions, so that a treatment of therayon threads with more than 2 different liquids without a mixing of thesame on the roller surfaces is made possible.

Figure 7 shows diagrammatically a front view of a roller pair and Figure8 is a corresponding side view. The upper roller 11 has a smoothsurface; it is however, di vided by a zigzag shaped interruption intotwo parts, so

that the liquids introduced through the lines 12 and 13 cannot becomemixed on the roller surface.

The axis of the lower roller 14 is oblique in relation to the axis ofthe roller 11. Consequently, in the rotation of the rollers the rayonthread 15 is led in a spiral shape, without special thread guide organsbeing necessary.

The roller 14 is likewise divided by a zigzag shaped interruption, sothat between the two parts there is a siit it as is more clearly shownin Figure 6. In the sense of the invention, the lower roller is providedwith grooves or projecting ledges running parallel to the a Is, throughwhich the carrying along of larger liquid quantities by the thread 15 isavoided.

What i claim is:

l. A device for treatment of artificial threads with liquids whichprevent the artificial threads from sticking to each other dui aftertreatment, comprising a it of cooperating upper and lower rolls havingtheir es inclincd to each other for advancing a thread thereover in aspiral path, the lower of said rolls having a surface of two sectionseach section consisting of contiguous longitudinal iiutings extendingradially outwardly, the surface of the tiutings converging at an acuteangle at the outer fiX- trcrnity thereof, the fiutings in one sectionbeing offset to a position between the fiutings of the other section ina circumferential direction, the fiutings having tooth-like portions onthe ends thereof which define a zigzag channel extendingcircumferentially around said lower roll, and means for introducingliquids to said upper roll.

2. A device as claimed in claim 1 in which the tooth-lilac portions ofsaid fluted surface extending into said zigzag channel in one directionextend past the tooth-like portions extending into said channel in theopposite direction, whereby a continuous longitudinal support forthreads is provided.

References Cited in the file of this patent UNITED STATES PATENTS1,578,241 Johnson Mar. 23, 1926 1,960,743 Junkers May 29, 1934 2,002,994Hartmann et al. May 28, 1935 2,020,057 Hartmann Nov. 5, 1935 2,259,202Cooper Oct. 14, 1941 2,263,440 Hansen Nov. 18, 1941 2,294,902 Gram Sept.8, 1942 2,356,026 Berry Aug. 15, 1944 2,416,533 Naumann Feb. 25, 19472,661,522 Lowe Dec. 8, 1953 FOREIGN PATENTS 217,892 Germany Jan. 15,l9l0

1. A DEVICE FOR TREATING OF ARTIFICIAL THREADS WITH LIQUIDS WHICHPREVENT THE ARTIFICIAL THREADS FROM STICKING TO EACH OTHER DURING AFTERTREATMENT, COMPRISING A PAIR OF COOPERATING UPPER AND LOWER ROLLS HAVINGTHEIR AXES INCLINED TO EACH OTHER FOR ADVANCING A THREAD THEREOVER IN ASPIRAL PATH, THE LOWER OF SAID ROLLS HAVING A SURFACE OF TWO SECTIONSEACH SECTION CONSISTING OF CONTIGUOUS LONGITUDINAL FLUTINGS EXTENDINGRADIALLY OUTWARDLY, THE SURFACE OF THE FLUTINGS CONVERGING AT AN ACUTEANGLE AT THE OUTER EXTREMITY THEREOF, THE FLUTINGS IN ONE SECTION BEINGOFFSET TO A POSITION BETWEEN THE FLUTINGS OF THE OUTER SECTION IN ACIRCUMFERENTIAL DIRECTION, THE FLUTINGS HAVING TOOTH-LIKE PORTIONS ONTHE ENDS THEREOF WHICH DEFINE A ZIGZAG CHANNEL EXTENDINGCIRCUMFERENTIALLY AROUND SAID LOWER ROLL, AND MEANS FOR INTRODUCINGLIQUIDS TO SAID UPPER ROLL.